1. Field of the Invention
The present invention relates to a camera equipped with a distance measuring device.
2. Related Background Art
Conventionally, as a camera, which is equipped with an active type distance measuring device, a camera disclosed in Japanese Unexamined Patent Application publication No. H-02-067529, is known. FIG. 15 is a graph showing a relationship between the distance to an object to be measured and distance signal (distance measuring property) in the distance measuring device. The broken lines in FIG. 15 represent the limits of a range of permissible circle of confusion, which means a permissible range of out-of-focus. Also, the width in the direction of the ordinate axis of these broken lines means the depth of focus at that distance. The camera is arranged so that the exposure control program in the camera is switched over depending on the distance measured by a distance measuring device, and thereby poor accuracy at a long range is compensated (refer to FIG. 15).
That is, this camera is arranged so that, in a short range where a satisfactory accuracy in the distance measurement is ensured (a range shorter than 1/L=0.13 in FIG. 15), a first exposure control program is used to release the aperture of lens; in a long range where the accuracy in the distance measurement is poor (a range longer than 1/L=0.13 in FIG. 15), a second exposure control program is used to narrow down the aperture of lens; thereby the depth of focus is increased to avoid out-of-focus.
[Patent Document 1]    Japanese Unexamined Patent Application publication (Tokukai) No. H-02-067529
[Patent Document 2]    Japanese Unexamined Patent Application publication (Tokukai) No. H-10-281756